1. Field of the Invention
The present invention relates generally to dairy inflations for extracting milk from an animal.
2. Description of Related Art
Milking equipment employing dairy inflations is used extensively in dairy operations in the United States. Many milking systems include a relatively hard or rigid outer shell within which is mounted a flexible, resilient dairy inflation. Such dairy inflations are also commonly referred to as liners or teat cups. Fluctuating, or cyclical, pressures are applied to an annulus between the shell and the outer surface of the dairy inflation to massage an animal's teat, which is held by the dairy inflation. The massaging of the teat causes the ejection of milk, which is then drawn through tubing to a centralized collecting vessel.
Dairy inflations made from silicone have typically had disadvantages compared to natural rubber inflations, one of which is due to the lower tear strength of silicone compounds. Low tear strength equates to a reduction in the number of milking cycles an inflation can perform during its useful life. Another disadvantage associated with some silicone compounds is the tendency of the compounds to absorb milk fat. High milk fat absorption can cause inflations to emit a bad odor with extended use. A third disadvantage is related to the relatively high drag coefficients associated with silicone compounds. Higher drag coefficients generally present a tackier surface, which can cause the inflation to climb the cow's udder during milking. This movement of the dairy inflation up the cow's udder usually causes the cow to kick the milking apparatus off, thereby interrupting the milking process. Another problem associated with silicone dairy inflations, which may also be prevalent in dairy inflations made from other materials, is premature rupture or tearing of the wall of the inflation in areas of reduced strength.
A need therefore exists for a dairy inflation compound that overcomes the disadvantages associated with synthetic, and more specifically silicone, dairy inflations. A need further exists for structural designs that will increase the effective life of the dairy inflation.